Pick Related Product
Warehouse->Products->{Click product}->[Related products]->[Add new related product]->[Pick Product]

Overview
Here you can pick a product to be a related product.

Elements
{the category name}
After you select a category, and the program will display the products in that category.
You'll see the product name and price, and will have a [Select] button to choose the desired attribute.


Links
From here you can:

Select a product [Select] Add Related Product page